Cyanogen chloride is the raw material for the production of cyanuric chloride, which is used in large amounts for manufacturing herbicides, optical brighteners, dyes and other end products. Cyanogen chloride is conventionally produced by reacting hydrocyanic acid and chlorine in an aqueous dilute hydrochloric acid solution, producing the following reaction: ##STR1## (Ullmann, Vol. 9, Page 652, 1975). In a concentrated aqueous acid medium, the cyanogen chloride is hydrolyzed as a function of the hydrochloric acid concentration. Under certain conditions, a reaction with the chlorine can form nitrogen trichloride from the ammonium chloride generated during hydrolysis. In order to prevent an excessive degree of hydrolysis from having a harmful effect upon the economy of the process, and also to substantially retard the production of nitrogen trichloride, which poses a serious danger to the apparatus and personnel, the hydrochloric acid concentration of the reaction medium is generally kept to 8 to 16 weight percent and preferably 10 weight percent. This process results in a considerable production of highly dilute aqueous hydrochloric acid, for which the equivalent contained in the chlorine reagent can no longer be achieved.
Another problem involved in this process is the recycling and/or elimination of the considerable amounts of this dilute hydrochloric acid.
Therefore, efforts have been made to develop a process in which the generation of hydrochloric acid is controlled in such a way that it constitutes no reduction or, at most, only a slight depreciation relative to chlorine. This has resulted in the process disclosed in German Auslegeschrift No. 18,01,311, wherein hydrogen cyanide and chlorine are caused to react in a non-aqueous, polar, organic fluid, inert with respect to the reactants and reaction products. However, this process results in only relatively low yields (54 to 85%) and, therefore, is not economical in view of the high cost of the raw materials.